Amplifying-hobn



R. A. WILLSON AMPLIFYING HORN.

APPLICATION HLED IULY 11. I9l8.

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Patented July 29, 191$).

2 SHEETS 'SHEET 1' R. A. WILLSON.

AMPLIFYING HORN APPLICATION FILED JULY 11, mus.

Patented July 29,19l9.

2 SHEETS SHEET 2.

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UNITED STATES PATENT OFFICE.

RUSSELL ,'.A. WILLSON, OFSPOKANE, WASHINGTON, ASSIG-NOR 0F ONE-HALF TO EMIL SIMON, OF SPOKANE, WASHINGTON.

AMPLIFYING-HORN.

7 To all w'hom z't-may concern:

Be it known that I, RUSSELL A. WILLSON a citizen of the United States, residing at Spokane, county of Spokane, and State of Washington, have invented certain new and useful Improvements in Amplifying-Horns, of whichthe following is a specification.

The present invention relates to improvements in amplifying horns or sound conveyers for phonographs, grap'hophones, and other talking machines.

In actual practice I have found that a sound conveyer or horn to give a clear cut. exactreproduction of a record, must. perform its functions so that each tone. conveyed through the horn will reach a certain focal point after having traveled overap proximately the same distance through the horn as has been traveled by other accompanying tones, in other words, the length of the sound waves or vibrations in the horn is the same. To accomplish this result I have provided an amplifying device that will retard certain waves, and advance other waves or vibrations, as they pass through the conveyer in order that their lengths may beuniform, and that all the waves or vibrations may be focused or centralized at the mouth of the horn, or slightly beyond. the mouth or opening of the horn.

. In the accompanying drawings I have illustrated one complete example of the physical embodiment of my invention, which in actual practice has successfully demonstrated the principles of the invention and this embodiment of the invention embodies the best mode I have so far devised for the practical application of the principles of the invention.

Figure 1 is a perspective view of a sound conveyer embodying the novel features of the present invention.

Fig. 2 is a rear view of the instrument.

Fig. 3 is a diagrammatic or plan view of the device laid out flat, disclosing the lines of the outline of the horn.

Fig. 4 is an enlarged diagrammatic view of the horn showing by dotted lines the course of numerous sound waves through the conveyer and illustrating the uniformity in length of these waves. f Inasmuch as the invention is confined particularly to the construction of the amplifier or horn, I have illustrated herein the Specification of Letters Patent. Patented July 29, 1919 Application filed July 11. 1918.

Serial No. 244.381.

device exclusively, which is somewhat of a U-shape arrangement, the horn proper being designated 1, the bent portion 2 and the amplifying portion prope'r is marked 3. The restricted inlet opening is 4, and the enlarged outlet opening, which is arranged on a plane at rightangles to the inlet openin 1, is marked 5.

liroughout the entire lengthof the device, it is rectangular in cross section, the horn proper having diverging walls, and the divergence extending beyond the bend 2, while the outlet end of the amplifying portion is provided with parallel walls. While the ent1re device is rectangular in cross section throughout 'itslength, the diverging walls are not uniform, and as a consequence, the horn is flattened somewhat between its inlet end and its outlet end to convey the sound waves or vibrations, and of course the diverging walls prov de an increasing area for the waves to expand.

Within the bend'2 of the device is arranged a reflecting surface 6, which is of" sufficient area to receive the incoming waves of sound or vibrations, and as the angleof reflection is equal to the angle of incidence,

each wave, asdiagrammatically indicated by dotted lines, is carried through the horn proper, strikes the reflecting surface and passes through the bend at the same angle in which it enters the bend, thus following a zig-zag course through the amplifier, for there is an oppositely disposed, second, reflectin surface as 7-near the mouth of the ampli er.

The reflecting surface 6 is curved as shown and starts at the base of thetapering horn, being in position to receive the sound waves as they are conveyed through the straight horn, and from the first point of incidence the sound waves are deflected and strike the surface 6 a second or a third time and are subsequently deflected until they encounter the second deflecting surface 7 As arranged in the hysical embodiment of the invention asin icated in F ig. 4 the sound waves strike the surface. 7 but a single time and thence are deflected to a common focal point 8, central of the mouth 5 and a little distance beyond the open mouth. The curved surface 6 is approximately circular, butv the curved deflecting surface 7, which is of much greater area just beyond the amplifier.

As is wellk no'wn, the tonewaves as they are conveyed through the horn and amplifier, have a tendency to swirl or travel in a spiral direction, with the result that an inferior tone is produced, but this objectionable feature is overcome by the rectangular construction, in cross section, of the device which provides dead air spaces along the corners of the horn and amplifier, which perform the function of friction surfaces and prevent the tones'or waves from so spiraling or swirling.

As best seen in Fig. i the lengths of the sound waves are all equalized (see dotted lines) and the sound waves travel over approximately the' same distance from one end of the conveyer to the other.

What I claim is 1.- A sound conveyer of-tortuou's shape and rectangular in cross section having diverging walls with opposed reflecting surfaces for equalizingl the length of the sound waves passing t erethrough.

2. A sound conveyer of tortuous shape rectangular in cross section having diverging curved walls with interior reflecting surfaces at its bends and oppositely disposed, for equalizing the length of the sound waves passing therethrough, and concentrating the Waves at a focal point beyond the open mouth of the conveyer.

3. A- sound conveyer comprising a straight horn portion, and an amplifier portion of tortuous shape provided with parallel side walls, said conveyer increasing in transverse area from end to end, and said amplifier portion having opposed diverging walls with reflecting surfaces at the interior of the bends to receive and reflect sound waves toward a common focal point.

In testimony whereof I afiix my signature.

RUSSELL A. WILLSON. 

